Yesterday, Howard programmed the XP10 on an OGD1 prototype board, put
it into a Linux PC, powered it on, and didn't see smoke.  Even better,
lspci reports that that the card is recognized as a VGA capable
device.  Although I had done lots of RTL-level simulation, that PCI
core has never before been tested in hardware, so it's pretty exciting
to see it handle config space correctly.

Howard is working on diagnostic code right now, what I was talking
about earlier.  This code will enable memory decode, map the memory
and register space, and perform initialization.  Once we have verified
that the XP10's internal memory-mapped registers are accessible, and
we can talk to its peripherals, we can program the Xilinx chip and get
it up and running, initialize memory, perform memory tests, start up
video, display a picture, etc.

Unfortunately, he's copying some code that we can't share, so we'll
still need someone to eventually write a Free version of this.  That
pushes the VGA BIOS and the HQ microcode up in priority.

The next tasks, things we really need help with, include:

- HQ microcode.  In the right mode, all PCI traffic to graphics memory
is routed through this tiny microprocessor.  It's primary purpose will
be to work in the background, converting the VGA text display into raw
pixels that can be scanned out by our video controller.  A lot of
information about VGA is on our wiki, but it may not be complete, so
we could use some help with that.  Personally, unless I'm tied up with
some other hardware issue, I'd be happy to write the microcontroller
code myself.  The hard part, really, is just knowing what to DO, so if
a few people could become experts on the details of things like the
VGA IO space registers and other stuff like that, it would help me
tremendously.

- VGA BIOS.  This should be something totally minimal.  Just enough to
set up video, program the HQ microcontroller, and get VGA text going.
There's a well-documented table that goes at the head of the PROM.  I
need some help with laying out some assembly code for that table and
the minimal VGA int10 stuff.  That should go on in parallel to the HQ
work.

- The DDX.  At first, we don't need a kernel driver.  Paul Brooks
wrote a DDX for OSCON, so it just needs to be hacked to work with the
register layout of this card.

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project
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